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. The [SSA Weather Burceu lo~eted at the Pueblo Meme- rial Airport supplies weather forecests four times daily for Pueblo, Colorado, eod vicinity. These forecasts are dissernioeted to local nOOlSOIedi<'ldirGctlybylimacdecGlIse telephone. A 51milar__but 5eperete*~in6telletion is weed for general public dissemination. In addition to the routine forecasts, special fore~este af Bevere storms or flood warnings ete issued as re- , qulred. A community flash flood reporting network of river and rein fall stations and e flood warning program developed end operated in connection with the 24-hcur Weather Bureau facili- ties could minimize lass of life e~d movable property in ths event of a major flood. Such en arrangement ~ould require that local river and rainfall reports be communioated promptly by responsible looal officials to the Weather Bureau Foreoest OfM fice for evaluation and analysis. If available, this data and analysis would be usod by the Weather Bureau to mOre acourately forewarn community representatives of potential storm and flood oonditions. This typ~ of n€t~ork i~ presently in effect in por- tions of the Arkansas Rivor basin and, to an extremely limited degree, in other tributary araas. . The Stream and Its Valley The St. Charles Rher origin"L,,;; ""'li' Sail babel, Colorado, on the northoast face of the Wet Mountains. After following e 50 mile northesoterly courso, its waters enter the Arkan'M River abOJt 6 ..iles "ast of Pueblo. In tho study reach, the river ha~ eroded into shale and limestone strata deposited during the Cretaceous age to form a narrow, entrenched valley within surrounding high pleins. This valley is bordered by bluffs that seidom exceed 30 feet in height. Valley widths range from ebout 1,200 feet in the upper ctudy reach to 3,000 feot"earthorivar'smouth,withSO<neisolatodsegments , 10 narro~ing to os little as 600 feat. Approximately 67 square miles of the upper watershed is aboveg,OOOfestinalavation. CreenhornMountain and St. Charlas Peak at elevations of 12,349 and 11,138 feet, respectively, are in this locality. The stre"",bed elevation at the mouth h about 4,545 feet. Stream siopes are relatively steep, avereging about 20 feet permllethroughthestudyreach. The tot"l 462 square mile water- shed includes the 232 square mile oontributing drainage "rea of the Greenhcrn River. As the principel tributary stream, the Greenhorn River joins the St. Charles River near the abandoned community of Lime about S miles south of Pueblo. The study reach lies primarily in the lower short-grass plein zone where native blue grema and galleta gresses with soma rabbit brush are found. Cottonwood, willow, and tamarisk (salt cedar) are the predominant trees growing along the channsl banks. The upper watershed vegetation consists of mixed conifers, such as pine, fir, and spruce, and typical mountain grasses including side- oats grama, needle, arizona faeque, and mountain muley. The river is a typical perennial mountain stream sus- tained by runoff fram sno.."elt end rainfall in the late hll, "'1n- , ter, and early spring. Runoff increases and flooding ocours during the Summer "'onth" in conjunction wi th increascd thunderstorm act1l1~ it1es. The average annual precipitation varies from about 12 inchM es at the mouth of the strs~m to 24 inches in the upper elellations of the watsrshed. Pertinent drainage arCas of the St. Charles Rivar arC given in Table 1. Developmonts in the FlOOd Plain Plahs 4 through 10sholll the floodplains of the St. Charles River for the reach covered by this report. In recant years, urbanization has gradually expanded into the lower valley to occupy Same flood pl~in lands that were formerly uaed for 11